Robert, Cruel Mercenary

When Robert, Cruel Mercenary enters the battlefield, investigate.
If at least {b}{b}{b} was spent to cast Robert, Cruel Mercenary, target player sacrifices a creature.
If at least {r}{r}{r} was spent to cast Robert, Cruel Mercenary, target player loses 5 life.
Whenever you sacrifice a clue, Robert, Cruel Mercenary gains +1/+1 until end of turn, and
deals 2 damage to target creature or player.